1. Field of the Invention
The present invention relates to unloading systems for open top rail cars. More particularly, the present invention relates to ramps whereby excavators can be driven toward the open top of the rail car so as to remove material from or introduce material the interior of the railcar.
2. Description of Related Art Including Information Disclosed Under 37 CFR 1.97 and 37 CFR 1.98
Railroads use open top cars to haul a variety of bulk cargo. Among the types of cars are hopper cars which have two, three, or four bays in which the bulk cargo is adapted to be unloaded by chutes in the bottom of each bay. Another type of railroad car used to haul the bulk cargo is the ore car which may have an unloading chute at the base of its structure. The third type of railroad car which hauls, on occasion, bulk cargo, is the gondola car which usually has much shorter sides than hopper cars and is used to haul a variety of cargo, not just bulk. The ore and hopper cars have high sides, usually reinforced to keep the pressure of the bulk ore or coal from pressing outwardly and caving in the sides. Some cars must be rotary dumped or unloaded from the top.
Both discrete products, such as lumber products, metal ingots, and products made discrete by packaging as in bags or the like, and particular, fungible products, such as sand, coal, gravel and grain, are frequently transported in open top containers, such as railway gondola cars.
In the prior art, the unloading of open top containers, such as hopper and gondola cars, has presented a variety of problems which have been dealt with by differing techniques in different situations. The techniques of the prior art for unloading open top containers, such as gondola cars, include manual unloading, the use of car dumpers, and the use of cranes, shovels or the like, for unloading. The prior art includes the use of a crane fixedly positioned alongside the railway tracks for unloading cars which are successively brought alongside the crane by being propelled along the track. The use of cranes, shovels, or backhoes supported atop fixed frame members which straddle railway tracks and the cars running thereon permits the material handling machine atop the frame to unload the cars contents as they run beneath the frame member. Shovels, backhoes and the like can also be installed upon moveable underframe members which straddle the tracks and support the material handling equipment at a height exceeding the height of the car being unloaded. Some ore and hopper cars are designed to be unloaded either by opening chutes on the bottom of their compartments or by being turned upside down with the section of track on in a huge unloader which rotates 180°. This is the ideal situation, but in most cases the use of such an unloader is not practical. This requires a complex structure underneath the track such that the bulk cargo can pour into it as it passes from the bottom of the hopper or ore cars.
When such equipment is not available, railroads and shippers have turned to expensive trackside unloading equipment, such as large traveling cranes similar to those that unload the holds of ships or stationary cranes able to pivot over the hopper cars. Such facilities are usually found at the shippers facility, at a major coal loading operation, or at a terminal at the dock for bulk being shipped by boat or at a major railroad yard.
In a great deal of the cases, such unloading equipment is just not available. Since there are new shippers of bulk and buyers of that bulk cargo coming on line constantly, there is a need for a simple, inexpensive loading and unloading apparatus which will do the job quickly and cheaply.
In the past, various patents have issued relating to the loading and unloading of open top railcars. For example, U.S. Pat. No. 5,066,188, issued on Nov. 19, 1991 to D. E. Bush, shows an apparatus for loading and unloading an open top railroad car by utilizing a conventional material handling equipment item attached to a slidable structure. The material handling equipment is equipped with a boom structure and material handling device. During railcar loading and unloading operations, the operator positions and attaches the material handling equipment item onto the slidable structure which is positioned adjacent to an end of the railcar. The front of the structure is engaged with the top surface of the railcar endwall and the material handling device is positioned on the railroad bed adjacent to the rear of the slidable structure. The boom structure is then extended to position the apparatus atop the railcar. The apparatus is then supported on the sidewall upper surface of the railcar by support members which are hydraulically extendable from the structure ends. The support members are equipped with stabilizer dogs which extend downwardly adjacent to the upper surface of the parallel sidewalls of the railcar for stability while loading and unloading material. The apparatus is moved forward or backward along the top of the railcar by a hydraulic winch mounted in the center of the slidable structure.
U.S. Pat. No. 5,342,159, issued on Aug. 30, 1994 to Warren, Jr., et al., provides an access and support apparatus for loading and unloading gondola cars using a crane-type crawler. There is a trailer-mounted ramp for disposition in close proximity to the railroad car. Multiple pallets are adapted for spanning the top width of the gondola railroad car and supporting the crane-type crawler. The crane-type crawler is unloaded from the trailer and traverses the ramp to the pallets. The pallets are sequentially moved from the rear to the front of the crane-type crawler as the crawler loads or unloads the railroad cars and traverses the length of the cars.
U.S. Pat. No. 5,733,091, issued on Mar. 31, 1998 to J. Long, describes rail transportable ramps for intermodal trains. This ramp has a pair of parallel, spaced ramp members each having a first end for engaging a ground level surface and a second end for engagement with a loading end of a rail car. A rigid cross-member extends between the ramp members adjacent the first ends. A flange is attached to the second ends of the ramp members for releasably coupling the ramp members to the rail car. The rail car has a slanted surface on each of opposite sides of the loading end for engaging the flange and restraining the ramp members. The rail car also incorporates rollers at the loading end for facilitating movement of the ramp members between a loaded position and a latching position.
U.S. Pat. No. 5,802,983, issued on Sep. 8, 1998 to C. J. Manzini, shows a railroad platform cart for the transport of heavy equipment, machinery and vehicles. The system includes a low-profile platform cart without motorization and a portable loading ramp for loading vehicles and such onto the cart. The cart also has a rear plow which is capable of removing ballast and debris from the tracks.
U.S. Pat. No. 6,190,106, issued on Feb. 20, 2001 to Richardson et al., provides an apparatus for loading open top railroad cars. This apparatus utilizes a crawler excavator having a pair of tracked treads and a hinged arm with a bucket thereon able to rotate a fill 360° and to move forward and rearward atop the open top railroad car. There is an attachment on the crawler with side extensions to hold the crawler atop the rail cars due to the side extensions slidably resting atop the sides of the rail car. There is provided a portable ramp by which the crawler excavator can mount the ends of the cars.
U.S. Pat. No. 6,561,742, issued on May 13, 2003 to Crawford et al., provides an apparatus for loading and unloading of railcars. This apparatus includes a mobile machine adapted to operate atop an open top rail car. A plurality of support subassemblies have surfaces adapted to engage upper surfaces of sidewalls of the rail car when the apparatus is positioned thereon. The support subassemblies are removable. The apparatus also has a boom structure with a bucket attached at an end thereof. The apparatus can move atop the rail car on its own power, or by coordinated use of the boom structure to push or pull the apparatus along the rail car.
U.S. Pat. No. 7,690,878, issued on Apr. 6, 2010 to C. W. Aaron, teaches a rail car having extendable ramp which is movable by a load bearing drive system. The ramp is stored under the deck of a rail car and can be extended by using the load-bearing drive system. The structure of the ramp includes a rail portion to allow the loading of rail-bound equipment, such as rail maintenance equipment, onto the deck of the rail car.
U.S. Pat. No. 4,830,562, issued on May 16, 1989 L. E. Frederking, provides a method and apparatus for loading and unloading a railroad. This apparatus has spaced-apart, parallel side walls with upper surfaces. The apparatus also includes a hydraulic excavator for the excavating, loading, and unloading materials. The excavator has a boom structure and a material-engaging device rotatably mounted on two tracks for moving the hydraulic excavator from one location to another. Each of the two track means has an inside set of rollers and an outside set of rollers for supporting the track over its entire width. There is provided an adjusting structure for moving the tracks inwardly and outwardly to vary the distance between the tracks. A track support apparatus supports the track connected to the adjusting structure. A plurality of arms are connected to the outside of each of the track support apparatus for preventing the hydraulic excavator from falling off of the gondola car when the two tracks are resting on the upper surfaces of the gondola car. The arms are adapted to extend downwardly adjacent to the upper surface of the parallel side walls of the railroad gondola car when the hydraulic excavator is located on top of the gondola car.
It is an object of the present invention to provide an apparatus for the unloading of an open top railcar which allows an excavator to be easily moved toward the top of the railcar.
It is another object of the present invention to provide a ramp apparatus whereby the length of the ramp can be configured to be easily moved on the bed of truck.
It is another object of the present invention to provide a ramp apparatus for the unloading of open top railcars which can be applied to the open top railcar without damage to the external safety appliances of the railcar.
It is still a further object of the present invention to provide a ramp apparatus for the unloading of open top railcars which provides the excavator with positive traction in all weather conditions.
It is still a further object of the present invention to provide a ramp apparatus for the unloading of open top railcars which has superior strength and durability.
It is still a further object of the present invention to provide a ramp apparatus for the unloading of open top railcars which is easy to use, relatively inexpensive and extremely adaptable.
These and other objects and advantages of the present invention will become apparent from a reading of the attached specification and appended claims.